Like it? Share it!

Tuesday, 4 September 2012

WPW Syndrome

#ECG class case 8

A 36 yrs old lady presents with history of ‘blackouts’.
Examination is entirely normal, as is her FBC and electrolytes.
The only possible explanation for her blackouts may lie in her abnormal ECG obtained below.What are your thoughts?

Discussion:

The ECG shows the ‘delta wave’ of Wolf Parkinson White (WPW) Syndrome. This may not
always be seen and can appear intermittently on different ECG’s on the same
patient. Often associated with a short
PR interval (<3 small squares, <0.12sec). Thus, it is one of a group of
conditions referred to as “pre-excitation” syndromes.

WPW is the commonest form of
Atrio-Ventricular Re-entrant tachycardias (AVRT).

The pre-excitation is caused by the
presence of an abnormal accessory conduction pathway between the atria and
ventricles. This pathway is called ‘The Bundle of Kent’. Impulses which travel down this pathway, will
cause the ventricles to contract prematurely. It is this premature contraction
of the ventricles, which give rise to the short PR interval and the delta wave.
In turn this can give rise to a supraventricular
tachycardia, or more specifically, an AVRT.

ECG Features of WPW:

·Short PR interval

·Widened QRS due to presence of delta wave – Slurring of the upslope of
the QRS complex:

HOWEVER, the ECG finding alone does not constitute
the ‘syndrome’.

To be truly diagnostic,
there needs to be a history of syncope/palpitations as a result of episodes of
Paroxysmal tachycardia.

So….What
Now?

Given that this lady has been having
symptoms, it would be safest to assume these are as a result of her WPW. She should be referred urgently to an
electrophysiologist cardiologist for risk stratification and further
management.